The invention relates to an anti-theft device for bicycles comprising one or more frame tubes and a pedal crank housing attached thereto.
Anti-theft devices with all kinds of different types of construction have been developed for preventing the unauthorized use of bicycles. For example, steel cable, chain or bow-type locking systems are known in the prior art, by means of which bicycles can be secured against theft. With such anti-theft devices, the bicycle is linked to, for example a stationary object (such as, for example a bicycle parking frame or the post of a street lamp, etc.) in order prevent its unauthorized use.
In addition to such separate types of construction, locking systems comprising securing steel cables of the type introduced, for example in GB 1 474 834, which are arranged on the bicycle, have become known as well.
Owing to the fact that the purchase costs of the bicycles are often relatively high, high-quality steel cable, chain or bow-type locks comprising high-quality locking systems are, of course, offered as well.
One of the major drawbacks of such high-quality security locks for bicycles is the high transport weight of the locking system, in particular the weight of the casing enclosing the locking system.
Therefore, it needs to be noted in general that in conformity with the current trend, high-quality bicycles are built with increasingly lighter weights, whereas the weight of the bicycle safety locks to be associated with such high-quality bicycles paradoxically becomes increasingly heavier at the same time.
Because of the low depth of installation of the safety lock, even the bicycle safety locks described in the prior art that are separately secured on the frame of the bicycle, can be forcibly opened through targeted manipulations even if such safety locks comprise the most stable type of construction of a steel cable, a chain or a bow, or by destroying the safety lock by force. This means that even with such types of construction of the safety lock that are connected with a high transport weight, the thief is able to drive away with a fully functioning bicycle after the lock has been broken open.
Now, other different variations of bicycle safety devices have been developed as well for preventing such xe2x80x9cdriving awayxe2x80x9d.
A system for locking the pedals of the bicycle has been introduced, for example in DE 195 31 315 A1. The rotational movement of the pedals of the bicycle is blocked by means of this locking system.
The drawback in conjunction with this type of construction is the fact that the thief, after he has pushed the bicycle, for example to a xe2x80x9csafe locationxe2x80x9d, can replace the pedals of the bicycle by a new pair of bicycle pedals after simply unscrewing and removing the original pair of pedals, and will quickly have again a fully functioning bicycle in this way.
It has been proposed in connection with other types of construction to block the pedal crankshaft by means of a locking system. Such locking systems for blocking the pedal crankshaft have been described earlier in NL 8100343, in DE 43 06 562 C2, and in EP 0 630 802.
However, the locking system described in the above documents can be used only in special types of construction of the frame, and cannot be fitted at a later time in most cases.
The locking system for blocking the pedal crankshaft introduced in DE 197 53 024 C2, which comprises a sleeve body that is formed by two bushes that can be pushed one into the other, whereby one bush is connected with the one and the other bush with the other of the two flanges, and whereby the blocking slide has to engage both bushes at the same time so as to prevent the flanges from being unscrewed in the locked condition after the pedals have been removed, can in fact be employed in a universal manner. However, this system requires high manufacturing and installation expenditures and, moreover, has a drawback in common with the pedal bearing blocking systems described already in the prior art, such disadvantage being the fact that the entire bicycle can be pushed or carried away in spite of the fact that the pedal crankshaft is locked with such a system. This means that it is not possible to prevent the theft of the entire bicycle, and it is neither possible to prevent the stolen bicycle from being dismantled at a later time into xe2x80x9cusable individual componentsxe2x80x9d.
If the thief destroys, for example the lightweight frame of the bicycle after he has pushed the bicycle away and has subsequently manipulated the blocked pedal crankshaft, and in case the complete bicycle has been recovered again, no insurance company will replace the frame that has been destroyed by the manipulations on the system blocking the pedal crankshaft.
Therefore, the present invention is based on the problem to eliminate the drawbacks mentioned above in connection with the prior art, and to develop an anti-theft device for bicycles that can be manufactured in a simple manner in terms of manufacturing technology. Such an anti-theft device prevents the bicycle from being pushed or carried away by unauthorized persons, and it is characterized by a very high-quality locking system that is difficult to access and has a low transport weight; that can be fitted at a later time on all types of different bicycle frame constructions and on any type of material of a bicycle frame (even on materials of the lightweight type) at low cost and with minor installation expenditure; and that, furthermore, prevents the frame of the bicycle from being destroyed even if sub-assemblies of the locking system have been subjected to extremely high stress due to forceful intervention.
Said problem is solved by means of an anti-theft safety device for bicycles comprising one or more frame tubes (1) and a pedal crankshaft guide (2) attached thereto, whereby a right-hand and a left-hand bearing receptacle (3) each accommodating an antifriction bearing (4) is supported in the pedal crankshaft guide (2) on the one and the other sides, and whereby a pedal crankshaft (5) is supported in said bearings in a rotating manner; whereby a chain sprocket wheel (6) with a pedal crank (7) is arranged on the one end of the pedal crankshaft (5), and a pedal crank (7) is arranged at the opposite end of the pedal crankshaft (5); with the pedal cranks each being screwed on either side to the pedal crankshaft (5) by means of a fixing screw (8).
In this connection, it is essential to the invention as well that the central through-extending bores (9) are arranged both axially in the pedal crankshaft (5) and axially in the fixing screws (8), and that the pedal crankshaft (5), which is dimensioned thicker with respect to its outside diameter in the mid-region (10), is provided in said region with a radial recess (11), in which both a lock housing (12) with a cylinder lock (13) and a slider (17) are arranged, whereby the key (14) of the cylinder lock (13) axially penetrates the fixing screw (8) located closest to the cylinder lock, but projects beyond said fixing screw with an actuator piece (15).
By virtue of the fact that the locking system is arranged in a low location in the pedal crankshaft and the installation depth is high at the same time in the middle of the pedal crankshaft, the locking system is difficult to access particularly for undesirable manipulations.
Furthermore, the xe2x80x9cprotectedxe2x80x9d accommodation of the cylinder lock in the middle of the functionally conditioned pedal crankshaft as defined by the invention, is characterized by an extremely low additional transport weight.
Furthermore, a characterizing feature is the fact that an eccentric pin (16) is arranged on the opposite face side of the cylinder lock (13). Via an eccentric pin guide (18), said eccentric pin is actively connected with a slider (17), which is arranged in a displaceable manner in the recess (11) on one face side. By turning the key (14) of the cylinder lock (13), the eccentric pin (16) moves in part of a circular track, and due to its cooperation with the eccentric pin guide (18), the latter being arranged on the slider (17), effects a progressive displacement of the slider (17) in its linear guides, which are arranged in the mid-region (10) of the pedal crankshaft (5).
It is important in this connection that a locking groove (19) provided with a center bore (21) is arranged in the face side of the slider (17) that is disposed opposite the eccentric pin guide (18). The locking head (23) of a lock pin (22) of a fastening system, which locking head can be inserted through the through-extending bore (9) in the opposite, second fixing screw (8) and the recess (11) in the pedal crankshaft (5), projects into said locking groove.
According to the invention, in the xe2x80x9cunlockedxe2x80x9d position, the central bore (21) of the slider (17) is located in the center position, so that the locking head (23) of the lock pin (22) can be fully inserted in the locking groove (19). Now, when the key (14) of the cylinder lock (13) is turned on its actuator piece (15), which is projecting beyond the fixing screw (8), the eccentric pin (18) moves in its circular track, and due to its cooperation with the eccentric pin guide (18) that is arranged on the slider (17), effects a progressive displacement of the slider (17) in its linear guide arranged in the mid-region (10) of the pedal crankshaft (5). The xe2x80x9carresting rangexe2x80x9d of the locking groove (19) not covered by the central bore slides in this connection into the free thrust zone (20) of the lock pin (22) immediately following the locking head (23), so that in this way, the lock pin (22) is exactly positioned xe2x80x9cin the pedal crankshaft (5)xe2x80x9d in the axial direction.
It is essential to the invention as well, furthermore, that the slider (17) can be provided with a greater height, i.e., it can be dimensioned in such a way that in the locking position, it xe2x80x9cdrives intoxe2x80x9d a recess (31) of a bearing receptacle (3) that is extended by a locking bush (32). What is effected at the same time by means of this arrangement as defined by the invention, with an exact axial positioning of the lock pin in the pedal crankshaft, is that the rotational freedom of the pedal crankshaft is blocked when the lock pin is arrested.
By virtue of this arrangement as defined by the invention, comprising, for example a chain, a locking bow etc., it is not possible to turn out the pedal crankshaft blocked by only one locking bush (32). Furthermore, due to the solution as defined by the invention, even the pedal cranks cannot be dismantled xe2x80x9cin the locked conditionxe2x80x9d.
Furthermore, it is a characteristic feature that the recesses (31) provided in the locking bush (32) are preferably arranged in such a manner that the slider (17) engages the recesses (31) always with the pedals being in the vertical position.
When the pedals are in such a vertical position, it is not possible, furthermore, to generate a high torque for the pedal crankshaft.
A further feature of the invention consists in that the pin head (24) with an adjacent ring guide (25) located on the side of the pedal crankshaft, is arranged on the end of the lock pin (22) of the fixing system projecting beyond the fixing screw (8), said ring guide having a locking ring (26) mounted on it, whereby a flexible securing element (27) such as, for example a high-tensile strip, a steel cable or a chain is secured on both the locking head (23) and the locking ring (26).
Now, before the locking head (23) is arrested, when the flexible securing element (27)xe2x80x94which is arranged with its one end on the pin head (24) and with its other end on the locking ring (26)xe2x80x94is looped, for example around a post, and additionally passed through the two wheels of the bicycle, the locking head (23) of the lock pin (22) can be arrested in the pedal crankshaft (5) as defined by the invention after the locking ring (26) has been plugged over the ring guide (25) of the lock pin (22).
Furthermore, it is essential to the invention as well that a separate connector piece (28) having a securing element (27) mounted on it, is arranged on the lock pin (22) in such a way that the lock pin (22) is connected with the connector piece (28) in a form-locked manner by affixing the locking ring (26) to it. This type of embodiment as defined by the invention is used when the anti-theft device comprising this variation of its construction is employed without blocking the pedal crankshaft in the locked condition, the purpose being in particular to minimize the transport volume of the sub-assemblies of the construction in their locked condition, and to permit the lock pin (22)xe2x80x94which is not provided with a securing element (27)xe2x80x94to remain in and, at the same, to be xe2x80x9clockedxe2x80x9d in the pedal crankshaft (5) when the bicycle is used for a ride, so that the lock pin (22), which is somewhat bulky because of its length (in the variation of the construction according to claim 1), then will not have to be transported separately. This type of construction of the solution as defined by the invention prevents soiling of the functional subassemblies of the construction arranged in the pedal crankshaft because the lock pin (22) remains in the through-extending bore (9). Owing to the design of the locking ring (26) and also of the pin head (24) as defined by the invention, said components being made of hardened or high-strength material; in conjunction with the arrangement of these components as defined by the invention directly in front of the fixing screw (8) of the pedal crank (7), any unauthorized dismantling of the pedal crankshaft (5) is prevented, as mentioned before, so that the solution as defined by the invention supplies the user with a high-quality locking system that is difficult to access; that has a low transport weight; and that can be fitted at a later time on all types of construction of bicycle frames and all types of materials of bicycle frames (even including the lightweight type of construction) at favorable cost; and, at the same time, prevents any destruction of the bicycle frame due to extreme stressing of the sub-assemblies of the locking system as a result of forceful intervention with this system.
Another variation of the embodiment of the invention is characterized in that a locking bow (33) is arranged on the lock pin (22). Now, this locking bow may connect, for example the pedal crankshaft, a pole or also a lamp post and different subassemblies of the frame with one another in a force-locked manner, so that any theft of the bicycle can be prevented in this way as well.
Furthermore, the fact that the locking ring (26), the pin head (24) and the locking bow (33) are made of hardened or high-strength material is important to the invention as well. On the side of the material, any intentional destruction of the anti-theft device as defined by the invention is counteracted by virtue of this special use of such a material.
Another characterizing feature is the fact that cover elements may be arranged on the through-extending bore holes (9) of the fixing screws (8) on one or both sides. Such cover elements prevent soiling of the functional subassemblies arranged in the pedal crankshaft (5) when the lock pin (22) is not inserted and/or the key (14) is removed.
It is essential, furthermore, that in connection with special types of construction, the key (14) can be pulled out only when the locking system is in the locked condition, so that on the one hand, any soiling of the functional subassemblies arranged in the pedal crankshaft can be counteracted, whereby in conjunction with these special types of construction, the key can be submitted, for example to insurance companies as evidence that the anti-theft device had been activated.
In addition to those contained in the text of the claims, additional features, details and advantages of the invention are revealed also in connection with the associated drawings and by the following explanations pertaining to the exemplified embodiments.